The aim of this research is to obtain basic information on the respiratory chain enzyme system of mitochondrial inner membrane so as to enable conclusions on obligatory carriers, their sequence, actions and mechanisms of the electron transport chain, as well as the role of the membrane in these processes, mainly by the methods of sequential fragmentation, systematic reconstitution, identification of the enzyme location (in the 3-dimensional sense), and related techniques. The resolved enzymes and components are first purified (crystallized, or crystallized in "2-dimensional" order as Henderson and Unwin in their studies of purple membrane, if possible) and then rigorously characterized by all conceivable but feasible physico-chemical and enzymic techniques including amino acid sequence, EPR, ENDOR electron microscopic image reconstruction, etc. It must be emphasized that reconstitution will be used as the most reliable method (until a better technique is found) to ascertain that no degradation or changes occurred during extensive purification of the components. True reconstitution in our sense is not just a functional coupling commonly used in biochemistry, but is a genuinely physical recombination; the recombined preparation should be identical with the intact one.